“Gutter oil” is one of the most revolting substances in the culinary pantheon. It sprang from the ingenuity of Chinese entrepreneurs, who fished out used cooking oil from drains, sewers and trash cans, decanted it into fresh bottles and sold it to an unsuspecting public.

On Jan. 7, the Jinan Intermediate People’s Court in eastern China handed out a suspended death sentence to a mastermind of one of the largest gutter-oil schemes ever recorded, worth more than $8 million in illicit sales. (A suspended death sentence usually means the convict escapes execution if no further crimes are committed.)

Seven others were sentenced to between five and 15 years in jail for the cooking-oil deception, according to state newswire Xinhua. In China’s lively microblog sphere, a slim consensus felt that the gutter-oil judgment was not harsh enough. Wrote one outraged person: “Criminals involved in food-safety issues should be sentenced to death and immediately executed.”

Gutter oil not only induces mental queasiness but it can also be laced with carcinogens. Its emergence is just one of many food scandals to befall China in recent years, as law enforcement has struggled to match the resourcefulness of unscrupulous traders. Every week brings news of a tainted or fake product, from deadly infant formula to glow-in-the-dark meat.

Just this week, abattoir workers in southern China were nabbed for injecting up to 6 kg of filthy pond water into each lamb carcass in order to bulk up its weight — and therefore price — at market. Last week, Walmart admitted that five-spiced donkey-meat treats sold in some of its Chinese stores were tainted by the addition of fox flesh. (Donkey is a common enough protein in northern China, but fox is not widely consumed.) Last fall, aficionados of skewered meat in Shanghai discovered the lamb they were savoring was actually rat.

The latest gutter-oil plot sprang from the minds of three brothers in eastern Shandong province, according to Xinhua. Beginning in 2006, the trio began selling dirty cooking oil to 17 dealers in two highly populated provinces. In October, in eastern Jiangsu province, a man was condemned to life imprisonment for using inedible animal fat, along with chicken feathers and fox fur, among other unusual substances, to bulk out the cooking oil he sold to more than 100 companies.

These convictions are part of a nationwide crackdown, with even state officials admitting the severity of China’s gutter-oil problem. Food-safety regulations have been tightened repeatedly since 2009. “Before in China, the punishment for violating food safety was very minor,” says Zheng Fengtian, a professor at the School of Agricultural Economics and Rural Development at Renmin University in Beijing. “You would just pay some fine and that would be it, so the cost of committing food-safety crimes was too low.”

But Zheng says there still is no nationwide standard on what constitutes safe cooking oil. Still, because of the current crackdown, he believes gutter oil is a waning phenomenon in Chinese kitchens. Zheng’s bigger concern is the widespread use of harmful pesticides and fertilizers in modern Chinese agriculture, with little oversight. “The issue of the origins of a food source will be a bigger problem for us to solve,” he says. Little wonder that food-safety concerns are among the top reasons given by Chinese who have recently quit their homeland for what they hope are cleaner pastures.